Fields, 53, was named Ford’s COO in December 2012. He has been leading all of Ford’s global business operations including product development, manufacturing, purchasing, and marketing, sales and service, the company said.

Mulally, 68, led Ford's turnaround since joining the company in September 2006 from running Boeing. With domestic rivals Chrysler and General Motors going through bankruptcy restructuring and a government bailout in 2009, it's easy to forget Ford had a close shave with bankruptcy, too.

Mulally's genius was to reduce the almost unbelievably complex plan to rescue Ford to a simple mantra that could fit on the back of a business card, or summed up even more briefly in two words: "One Ford."

“One Ford” stands for reining in Ford’s global operations and getting them all working on the same agenda. Historically, Ford’s overseas subsidiaries were semi-autonomous. There was a lot of duplicated effort. The classic example is that Ford of Europe and Ford North America developed separate versions of the compact Ford Focus with almost no common components, even though they were aimed at the same demographic.

Starting with the 2012 Ford Focus, the new car was moved to a global platform with sales of more than two million units worldwide, instead of a few hundred thousand here, and few hundred thousand there. That strategy that generates huge economies of scale, with 10 different Ford models on the same underpinnings, sharing common parts in areas customers never see. Different models are also designed to be built on the same assembly line, so production can be shifted to meet demand.

Under Mulally, Ford also shed non-core brands that in the final analysis were nice to have, but not absolutely necessary to have, like Volvo, Jaguar, Land Rover, and even Mercury.

These are basic concepts the U.S. auto industry knew for years it needed to adopt to compete in increasingly global, interconnected markets, but it took the shock of the Great Recession to shake things loose. Mulally was just the right executive at the right time to preside over putting things back together.